[PATCH] arm64: dts: qcom: sc8280xp: use refgen regulator for DSI

[PATCH] arm64: dts: qcom: sc8280xp: use refgen regulator for DSI

[Pengyu Luo]

Use it for the DSI controllers, since DSI nodes have been added.

Signed-off-by: Pengyu Luo <mitltlatltl@gmail.com>
---
This patch depends on the below series:
https://lore.kernel.org/linux-arm-msm/20260228101907.18043-1-mitltlatltl@gmail.com/
---
 arch/arm64/boot/dts/qcom/sc8280xp.dtsi | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/sc8280xp.dtsi b/arch/arm64/boot/dts/qcom/sc8280xp.dtsi
index 79021267d..1599d698b 100644
--- a/arch/arm64/boot/dts/qcom/sc8280xp.dtsi
+++ b/arch/arm64/boot/dts/qcom/sc8280xp.dtsi
@@ -4843,6 +4843,8 @@ mdss0_dsi0: dsi@ae94000 {
 				operating-points-v2 = <&dsi_opp_table>;
 				power-domains = <&rpmhpd SC8280XP_MMCX>;
 
+				refgen-supply = <&refgen>;
+
 				phys = <&mdss0_dsi0_phy>;
 				phy-names = "dsi";
 
@@ -4942,6 +4944,8 @@ mdss0_dsi1: dsi@ae96000 {
 				operating-points-v2 = <&dsi_opp_table>;
 				power-domains = <&rpmhpd SC8280XP_MMCX>;
 
+				refgen-supply = <&refgen>;
+
 				phys = <&mdss0_dsi1_phy>;
 				phy-names = "dsi";
 
@@ -6398,6 +6402,8 @@ mdss1_dsi0: dsi@22094000 {
 				operating-points-v2 = <&dsi_opp_table>;
 				power-domains = <&rpmhpd SC8280XP_MMCX>;
 
+				refgen-supply = <&refgen>;
+
 				phys = <&mdss1_dsi0_phy>;
 				phy-names = "dsi";
 
@@ -6478,6 +6484,8 @@ mdss1_dsi1: dsi@22096000 {
 				operating-points-v2 = <&dsi_opp_table>;
 				power-domains = <&rpmhpd SC8280XP_MMCX>;
 
+				refgen-supply = <&refgen>;
+
 				phys = <&mdss1_dsi1_phy>;
 				phy-names = "dsi";
 
-- 
2.53.0

Re: [PATCH] arm64: dts: qcom: sc8280xp: use refgen regulator for DSI

[Dmitry Baryshkov]

On Sat, Feb 28, 2026 at 08:54:30PM +0800, Pengyu Luo wrote:
> Use it for the DSI controllers, since DSI nodes have been added.
> 
> Signed-off-by: Pengyu Luo <mitltlatltl@gmail.com>
> ---
> This patch depends on the below series:
> https://lore.kernel.org/linux-arm-msm/20260228101907.18043-1-mitltlatltl@gmail.com/

Why was it not squashed into that series? I'd assume that DSI nodes are
incomplete and are working "by luck" without the refgen supplies.

> ---
>  arch/arm64/boot/dts/qcom/sc8280xp.dtsi | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/qcom/sc8280xp.dtsi b/arch/arm64/boot/dts/qcom/sc8280xp.dtsi
> index 79021267d..1599d698b 100644
> --- a/arch/arm64/boot/dts/qcom/sc8280xp.dtsi
> +++ b/arch/arm64/boot/dts/qcom/sc8280xp.dtsi
> @@ -4843,6 +4843,8 @@ mdss0_dsi0: dsi@ae94000 {
>  				operating-points-v2 = <&dsi_opp_table>;
>  				power-domains = <&rpmhpd SC8280XP_MMCX>;
>  
> +				refgen-supply = <&refgen>;
> +
>  				phys = <&mdss0_dsi0_phy>;
>  				phy-names = "dsi";
>  
> @@ -4942,6 +4944,8 @@ mdss0_dsi1: dsi@ae96000 {
>  				operating-points-v2 = <&dsi_opp_table>;
>  				power-domains = <&rpmhpd SC8280XP_MMCX>;
>  
> +				refgen-supply = <&refgen>;
> +
>  				phys = <&mdss0_dsi1_phy>;
>  				phy-names = "dsi";
>  
> @@ -6398,6 +6402,8 @@ mdss1_dsi0: dsi@22094000 {
>  				operating-points-v2 = <&dsi_opp_table>;
>  				power-domains = <&rpmhpd SC8280XP_MMCX>;
>  
> +				refgen-supply = <&refgen>;
> +
>  				phys = <&mdss1_dsi0_phy>;
>  				phy-names = "dsi";
>  
> @@ -6478,6 +6484,8 @@ mdss1_dsi1: dsi@22096000 {
>  				operating-points-v2 = <&dsi_opp_table>;
>  				power-domains = <&rpmhpd SC8280XP_MMCX>;
>  
> +				refgen-supply = <&refgen>;
> +
>  				phys = <&mdss1_dsi1_phy>;
>  				phy-names = "dsi";
>  
> -- 
> 2.53.0
> 

-- 
With best wishes
Dmitry

Re: [PATCH] arm64: dts: qcom: sc8280xp: use refgen regulator for DSI

[Pengyu Luo]

On Sat, Feb 28, 2026 at 9:13 PM Dmitry Baryshkov
<dmitry.baryshkov@oss.qualcomm.com> wrote:
>
> On Sat, Feb 28, 2026 at 08:54:30PM +0800, Pengyu Luo wrote:
> > Use it for the DSI controllers, since DSI nodes have been added.
> >
> > Signed-off-by: Pengyu Luo <mitltlatltl@gmail.com>
> > ---
> > This patch depends on the below series:
> > https://lore.kernel.org/linux-arm-msm/20260228101907.18043-1-mitltlatltl@gmail.com/
>
> Why was it not squashed into that series? I'd assume that DSI nodes are
> incomplete and are working "by luck" without the refgen supplies.
>

I had completely forgotten about it until I found the patch when I was
sorting these old day unverified patches. At that time, I just sent
DSI patches. I will put it into DSI patches.

Many platforms should work without refgen. Bootloder may have
initialized it and be untouched later? Once there was no refgen
regulator, my sdm845 phone worked.

Best wishes,
Pengyu

Re: [PATCH] arm64: dts: qcom: sc8280xp: use refgen regulator for DSI

[Dmitry Baryshkov]

On Sat, Feb 28, 2026 at 09:38:43PM +0800, Pengyu Luo wrote:
> On Sat, Feb 28, 2026 at 9:13 PM Dmitry Baryshkov
> <dmitry.baryshkov@oss.qualcomm.com> wrote:
> >
> > On Sat, Feb 28, 2026 at 08:54:30PM +0800, Pengyu Luo wrote:
> > > Use it for the DSI controllers, since DSI nodes have been added.
> > >
> > > Signed-off-by: Pengyu Luo <mitltlatltl@gmail.com>
> > > ---
> > > This patch depends on the below series:
> > > https://lore.kernel.org/linux-arm-msm/20260228101907.18043-1-mitltlatltl@gmail.com/
> >
> > Why was it not squashed into that series? I'd assume that DSI nodes are
> > incomplete and are working "by luck" without the refgen supplies.
> >
> 
> I had completely forgotten about it until I found the patch when I was
> sorting these old day unverified patches. At that time, I just sent
> DSI patches. I will put it into DSI patches.
> 
> Many platforms should work without refgen. Bootloder may have
> initialized it and be untouched later? Once there was no refgen
> regulator, my sdm845 phone worked.

If there is no refgen driver, then the bootloader setup will continue to
work since nobody touches it. If there is a refgen driver, then the
kernel will shut it off during the bootup procedure.

-- 
With best wishes
Dmitry

Re: [PATCH] arm64: dts: qcom: sc8280xp: use refgen regulator for DSI

[Pengyu Luo]

On Sat, Feb 28, 2026 at 9:44 PM Dmitry Baryshkov
<dmitry.baryshkov@oss.qualcomm.com> wrote:
>
> On Sat, Feb 28, 2026 at 09:38:43PM +0800, Pengyu Luo wrote:
> > On Sat, Feb 28, 2026 at 9:13 PM Dmitry Baryshkov
> > <dmitry.baryshkov@oss.qualcomm.com> wrote:
> > >
> > > On Sat, Feb 28, 2026 at 08:54:30PM +0800, Pengyu Luo wrote:
> > > > Use it for the DSI controllers, since DSI nodes have been added.
> > > >
> > > > Signed-off-by: Pengyu Luo <mitltlatltl@gmail.com>
> > > > ---
> > > > This patch depends on the below series:
> > > > https://lore.kernel.org/linux-arm-msm/20260228101907.18043-1-mitltlatltl@gmail.com/
> > >
> > > Why was it not squashed into that series? I'd assume that DSI nodes are
> > > incomplete and are working "by luck" without the refgen supplies.
> > >
> >
> > I had completely forgotten about it until I found the patch when I was
> > sorting these old day unverified patches. At that time, I just sent
> > DSI patches. I will put it into DSI patches.
> >
> > Many platforms should work without refgen. Bootloder may have
> > initialized it and be untouched later? Once there was no refgen
> > regulator, my sdm845 phone worked.
>
> If there is no refgen driver, then the bootloader setup will continue to
> work since nobody touches it. If there is a refgen driver, then the
> kernel will shut it off during the bootup procedure.
>

Thanks for explaining this. I saw a similar thing on sm8750, I had to
reboot again and again to turn on the display once.

Best wishes,
Pengyu

Re: [PATCH] arm64: dts: qcom: sc8280xp: use refgen regulator for DSI

[Pengyu Luo]

On Sat, Feb 28, 2026 at 9:13 PM Dmitry Baryshkov
<dmitry.baryshkov@oss.qualcomm.com> wrote:
>
> On Sat, Feb 28, 2026 at 08:54:30PM +0800, Pengyu Luo wrote:
> > Use it for the DSI controllers, since DSI nodes have been added.
> >
> > Signed-off-by: Pengyu Luo <mitltlatltl@gmail.com>
> > ---
> > This patch depends on the below series:
> > https://lore.kernel.org/linux-arm-msm/20260228101907.18043-1-mitltlatltl@gmail.com/
>
> Why was it not squashed into that series? I'd assume that DSI nodes are
> incomplete and are working "by luck" without the refgen supplies.
>

Today, I did a casual read. I found the register(0x8900000 + 0x80) to
enable refgen is always 0 on windows. The refgen driver may be not
compatible with sc8280xp or the DT configuration is wrong.

Best wishes,
Pengyu

Re: [PATCH] arm64: dts: qcom: sc8280xp: use refgen regulator for DSI

[Konrad Dybcio]

On 4/17/26 2:23 PM, Pengyu Luo wrote:
> On Sat, Feb 28, 2026 at 9:13 PM Dmitry Baryshkov
> <dmitry.baryshkov@oss.qualcomm.com> wrote:
>>
>> On Sat, Feb 28, 2026 at 08:54:30PM +0800, Pengyu Luo wrote:
>>> Use it for the DSI controllers, since DSI nodes have been added.
>>>
>>> Signed-off-by: Pengyu Luo <mitltlatltl@gmail.com>
>>> ---
>>> This patch depends on the below series:
>>> https://lore.kernel.org/linux-arm-msm/20260228101907.18043-1-mitltlatltl@gmail.com/
>>
>> Why was it not squashed into that series? I'd assume that DSI nodes are
>> incomplete and are working "by luck" without the refgen supplies.
>>
> 
> Today, I did a casual read. I found the register(0x8900000 + 0x80) to
> enable refgen is always 0 on windows. The refgen driver may be not
> compatible with sc8280xp or the DT configuration is wrong.

The Linux driver casts a software vote. Most newer SoCs should have
a separate hw line between the PHYs and the REFGEN regulator to take
care of it automatically.

Even if a little unnecessary, this won't hurt

I *think* base+0xc & BIT(3) should tell you whether the power is
actually flowing at a given moment

Konrad

Re: [PATCH] arm64: dts: qcom: sc8280xp: use refgen regulator for DSI

[Pengyu Luo]

On Fri, Apr 17, 2026 at 8:37 PM Konrad Dybcio
<konrad.dybcio@oss.qualcomm.com> wrote:
>
> On 4/17/26 2:23 PM, Pengyu Luo wrote:
> > On Sat, Feb 28, 2026 at 9:13 PM Dmitry Baryshkov
> > <dmitry.baryshkov@oss.qualcomm.com> wrote:
> >>
> >> On Sat, Feb 28, 2026 at 08:54:30PM +0800, Pengyu Luo wrote:
> >>> Use it for the DSI controllers, since DSI nodes have been added.
> >>>
> >>> Signed-off-by: Pengyu Luo <mitltlatltl@gmail.com>
> >>> ---
> >>> This patch depends on the below series:
> >>> https://lore.kernel.org/linux-arm-msm/20260228101907.18043-1-mitltlatltl@gmail.com/
> >>
> >> Why was it not squashed into that series? I'd assume that DSI nodes are
> >> incomplete and are working "by luck" without the refgen supplies.
> >>
> >
> > Today, I did a casual read. I found the register(0x8900000 + 0x80) to
> > enable refgen is always 0 on windows. The refgen driver may be not
> > compatible with sc8280xp or the DT configuration is wrong.
>
> The Linux driver casts a software vote. Most newer SoCs should have
> a separate hw line between the PHYs and the REFGEN regulator to take
> care of it automatically.
>
> Even if a little unnecessary, this won't hurt
>
> I *think* base+0xc & BIT(3) should tell you whether the power is
> actually flowing at a given moment
>

I see. Thanks for your explanation!

Best wishes,
Pengyu

> Konrad